Resilient printing die



Feb. 14, 1961 M. v. JOHNSON, JR., EIAL 2,971,459

RESILIENT PRINTING DIE 5 Sheets-Sheet 1 Original Filed Feb. 2, 1956 Feb.14, 19 1 M. v. JOHNSON, JR., ETAL 2,971,459

RESILIENT PRINTING DIE 5 Sheets-Sheet 2 Original Filed Feb. 2, 1956 5 R3 MN N W v 0 w 5L MI/M M0 M Feb. 14, 1961 M. v. JOHNSON, JR., EIAL2,971,459

RESILIENT PRINTING DIE 5 Sheets-Sheet 5 Original Filed Feb. 2, 1956iiimhi;

INVENTORS."

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RESILIENT PRINTING DIE Original Filed Feb. 2, 1956 5 Sheets-Sheet 4 mun-IN V EN TORS.

Feb. 14, 1961 M. v. JOHNSON, JR., EIAL 2,971,459

RESILIENT PRINTING DIE Original Filed Feb. 2, 1956 5 Sheets-Sheet 5 9 7'TOP/VEKS United States Patent" RESILIENT PRINTING DIE Maurice V.Johnson, Jr., Upland, and Donald C. Savage, Ontario, Calif., assignorsto Sunkist Growers, Inc., Los Angeles, Calif., a corporation ofCalifornia Original application Feb. 2, 1956, Ser. No. 563,045. Di-

;i6d1eg53nd this application Sept. 15, 1958, Ser. No.

2 Claims. (Cl. 101-379) This invention relates to printing machines andmore particularly to a machine especially capable of printing citrusfruit, eggs, apples, cantaloupes, nuts, potatoes, avocados, tomatoes andother substantially cross sectionally circular objects.

This is a divisional application of our copending application Serial No.563,045, filed February 2, 1956, entitled Printing Machine.

Our invention will be disclosed with specific reference to the printingof trademarks or other indicia upon lemons, since that fruit, clue toits ellipsoidal shape, variance in diameter from fruit to fruit andirregular and easily bruised surface, is difiicult to effectively print.It will be apparent, however, that our machine is eminently adapted toprint other fruits, nuts, vegetables or articles of manufacture whichhave a substantially circular cross section.

While many fruit and vegetable stampers or markers have been proposed,the printing of lemons with trademarks has not yet been accomplishedcommercially and there is not yet known a machine which willsatisfactorily serve this function. The obovate to ellipsoidal form ofthe lemon renders it necessary to orient the friut so that in passingthrough the printing assembly the smoothest, most gently rounded surfaceof the fruit is presented to the printing die. If the fruit is contactedby the die at either its stem or blossom end, it is evident that a trueimpression of the indicia will not be obtained. In addition to theproblems resulting from the shape of the lemon, further problems arecreated by their large variation in size. The diameter of an averagelemon is about 2 /8 inches but this varies from as little or less than 1/2 inches to as much as 3 /8 inches or more; consequently a print ingmachine will not successfully print lemons which have not beenpreviously classified as to size unless it is capable of properlyfunctioning over at least this size range. The problem is furthercompounded by the fact that lemons grown in the Pacific coastal areasand in other areas having cooler climates, which account for a largepercentage of the lemon production of the United States, lack resiliencyand have an irregular relatively stiff inflexible peel easily subject todamage by bruising. These characteristics make it impossible to relyupon cornpression of the fruit itself to compensate for variation insize from fruit to fruit, which would be required. if the support to diedistance were fixed and unyielding. Irrespective of the size of fruitpassing through the print ing assembly, it is essential that there be afirm but not severe contact between every part of the die and the lemonat the time of printing. If the contact is not firm enough the indiciawill not be clearly printed upon the lemon, while if it is too firm, thedie may rupture the peel and possibly inoculate it with, mold spores orbacteria or in any event render the fruit subject to future inoculation.

A further difliculty involves the requirement that there besubstantially no relative velocity between the die and the lemon surfacebeing printed. If there is such relalCe tive velocity, i.e., if thelemon surface is moving past the die at a velocity less than or greaterthan that of the die, the die will not impress its designation clearlybut will produce a smeared unreadable mark.

It will be evident that any printing machine suitable for utilization inthe printing of random sizes of lemons must be capble of orienting andaligning the fruit; it must be capable of printing constantly changingsizes of lemons; it must provide a firm but not severe contact betweenthe die and the fruit; and it must function in such manner that there issubstantially no relative velocity between the die and the fruit. Ofcourse, it must, in addition, be capable of handling large volumes of;fruit at a minimum cost, f

It is therefore one of the objects of our invention to provide aprinting die for use in a machine fulfilling all of the requirements setforth in the preceding paragraph.

Further objects of our invention will become apparent from aconsideration of the drawings in which:

Figure 1 is an elevation showing the right hand side of our machine;

Figure 2 is a sectional view through the printing drum, printing tube,and a portion of the conveyor;

Figure 3 is an elevation view of the printing tube, printing drum, and aportion of the conveyor with parts shown in section;

Figure 4 is an elevation showing the left hand side of our machine, partof the conveyor being omitted;

Figure 5 is a detail view, partly in section, of a portion of theprinting drum of our machine; and

Figure 6 is a perspective view of an improved form of a printing die.

With more specific reference to the drawings, our machine, which is'mounted upon suitable supporting frames 1 and 2, is composed of anorienting conveyor 3, a rotary printing drum 4 and an inking ribbon tube5 all driven by a motor 6 or other suitable driving means.

As shown in Figure 3, the ribbon tube, printing drum and conveyor driveshafts are rotatably mounted in bearings 7 secured by bolts 8 to sideframes -9 which are in turn secured to supporting cross members 10(Fig. 1) attached to supporting frame 2. The ribbon tube 5 is fixed tostub shafts 11 and 12 while the printing drum 4 is mounted on shaft 13.Conveyor drive shaft 14 is provided for supporting conveyor sprocketsand platens hereinafter described. Shafts 13 and 14 are parallel to eachother and to ribbon tube shafts 11 and 12. The conveyor drive shaft isdriven (Figure l) by chain 15 which is trained over sprocket 16 on themotor shaft and sprocket 17 on conveyor shaft 14. If desired, arsuitablechain tension adjusting mechanism, such as, sprocket 1 8 rotatablymounted on adjustable bracket 19, may be provided. Gear 20 secured toshaft 14 meshes with gear 21 keyed to shaft 13. Another gear 22 attachedto the shaft 13 exteriorly of gear 21 engages and drives gear 23 securedto shaft 12. Through this drive arrangement the conveyor drive shaft,printing drum and ribbon tube are rotated in the directions indicated bythe arrows in Figure 2.

The orienting conveyor is supported at its delivery end upon drive shaft14. The receiving end of the conveyor is supported on shaft 25 mountedin bearings 28 in. side plates 24 fixed to support frame 1. A pair ofsprockets 26 are mounted at opposite ends of the shaft 25 in alignmentwith, a pair of sprockets 27 secured to drive. shaft 14. Bearings 28(Figure 1) are. longitudinally adjustable by a conventional take-updevice 29 secured to the, side plates of the conveyor unit. Conveyorchains 30 are trained over the corresponding sprockets on shafts 14 and25. Alternate individual links 31 of the chain are provided withjournals 32 upon which rollers 33 are. rotat ably mounted.

Referring to Figure 2 the individual rotating rollers 33 of the conveyorunit 3 consist of cylinders 37 of suitable material, such as aluminum,upon which intermediate annular sleeves 38 and a pair of end sleeves 3hare secured. The sleeves are of trapezoidal longitudinal half sectionand are preferably made of rubber to avoid' injury to the lemons.Arcuate annular grooves 42 are formed in each of the cylinders 37 atpoints midway between the sleeves.

It will be noted from a consideration of Figures 1 and 3 that thegrooves 42 are in alignment with printing dies.45. These grooves are ofarcuate form but not of suflicient width or depth to receive or contactthe major Surface of the lemons.

Securely mounted upon conveyor drive shaft 14 are a plurality of rotaryplatens 48 (Figure 2) having spokes 49 which extend between adjacentrollers and assist in supporting the fruit during the printing thereof.In order to properly perform their supporting function, the spokes areso arranged and of such length as to extend into pockets 44 between therollers to the circle of revolution defined by the rotation of the axisof each of the rollers about the shaft 14. The width of the spokes isless than the distance between adjacent cylinders 37 but greater thanthe distance between the sleeves 38. In addition, the spokes are nogreater in thickness than the dimension 40. If desired, each spoke maybe tipped As shown in Figure 2, we provide a delivery board 159 for ourconveyor. This is secured to the side plates 24 and is provided with aplurality of fingers or guides 160 mounted at positions correspondingwith the locations of the sleeves 38 of each individual roller. Whilethese guides assist in assuring that individual aligned pockets such asthose indicated by the reference numeral 44 receive only a single fruit,they are not essential to the proper functioning of our conveyor unit. Asuitable board 161 is provided to receive printed fruit delivered fromthe machine.

Although die 45 may be constructed of any suitable material such asrubber or other flexible resilient material and may be solid inlongitudinal as well as transverse cross section, we have discoveredthat the desired impression of the mark upon the fruit may be obtainedby utilizing the inventive details shown in Figure 6 while substantiallyincreasing the operative life of the die and completely avoiding anypossibility of rupturing the skin with rubber 50 or other flexible,resilient material in order 'to provide a somewhat yielding supportingsurface that will not injure the fruit.

As best seen in Figures 2 and 5, the printing drum assembly 4 iscomposed of shaft 13 and segmental die holders'Sl secured on the shaftby retaining bars 52, which are detachably secured to shaft 13 by springlock assembly 53. The shaft 13 is square in cross section throughout itslength except for journal portions 54 at each end, which are journaledin the bearings 7. The retaining bars 52 are long strips and, as shownin Figure 2, are flanged along their longitudinal edges at an angle fromthe flat portion of said retaining bars. These edges are in additionbent toward one another to provide inwardly extending flanges 62. Thebase portion 63 of theretaining bars 52 is flat and abuts against a flatsurface portion of the shaft 13. This shaft is provided at anintermediate portion or at its opposite end with a retaining flange 64on each of the flat portions of the shaft. One end 65 of the bar 52 isretained between the surface of the shaft 13 and the flange 64. Itwillbe apparent that each bar 52 is detachably secured to theflatsurfaces of shaft 13.

' Referring to Figure 2 the segmental die holders 51 are constructed ofrubber, sponge rubber or other flexible resilient material and areprovided with slots into which the flanges 62 fit to removably securethe holders to the retaining bars. The printing dies 45 are wedged orkeyed into openings provided in the circumferential portion of the dieholder segments. The segments may be provided with cavities 66 of anydesired size of shape to provide the requisite flexibility of thesegments depending on the nature of the material used in theirfabrication.

At each end of the inking ribbon tube is a ribbon drive gear, not shown,which drives the shaft on which ribbontake-up spools 77 are detachablymounted for rotation therewith.

As illustrated in Figure 2 inking ribbon 96 is withdrawn from the feedspool 95, inserted through ribbon feed slot 101, woundiabout the ribbontube in a clock wise'dire'ction, inserted back through slot 101 andattached to take-up spool 77. As tube 5 rotates in a clockwise directionas shown in Figure Z, the inking ribbon'96 is drawnover..the'outersurface of the ribbon tube and wound; up'on'sp'ooli77;thus constantly renewing the inking ribbon which contactsthedies'i45;When the of the lemon. I

The die of Figure 6, which is generally identified by the referencenumeral 162, takes the form of an isosceles trapezoid in transverse andlongitudinal section. The face 163 contains the letters or symbols whichit is desired to print on the fruit, while the back hasa peripheralrounded flange 164 protruding therefrom about the entire peripherythereof, including its sides and ends. This flange permits easyinsertion into and retention of the die about its entire base by the dieholders 51 as illustrated for the die 45 in Figure 10. A plurality oftransverse parallel slits 165 extend through the flange 164 and acentrally located longitudinal slit 167 similarly extends through theflange 164. Slits 165 and slit 167 extend partly into the body portion166 of the die. The longitudinal andtransverse slits combined with thenovel shape of our die greatly increase .its overall flexibility andcompressibility without appreciably decreasing the rigidity of thenumerals or symbols on its face.

We have also discovered that the flexibility of die 162 can be furtherincreased without appreciably decreasing the rigidity of the numerals orsymbols by constructing the die in such manner that the indicia and bodyportion closest to the indicia are made of a harder rubber than theremaining portion of the die. This can be accomplished during themolding process by first inserting a rubber having a Shor hardness ofabout 70 and filling the remainder of the mold with a rubber having aShot hardness of about 40 before exerting heat and pressure upon themold to cause some commingling of the two rubber materials, as will bereadily understood. The re sulting die has a soft resilient back and arelatively rigid face, and has a body portion of progressivelydiminishing rigidity as the back is reached.

. fruit to a receiving conveyor, a sizer or to other lemon iibbon iscompletely used,.the spoolsar removed from treating apparatus. Uponoperation of the motor 6, drive chain 15 rotates the sprocket 17 on theshaft 14, thus rotating sprockets 27 which drive the pair of chains 30and move the upper run of conveyor rollers toward the printing drum. Asthese rollers progress they ae contacted by a roll actuating member 46,which causes each roller to'rotate in a clockwise direction as viewed inFigure 2. This rotation permits the retention of but a single fruitwithin the individual pockets 44 defined by adjacent rollers 33. Aspreviously noted, the rotation and the particular shape of these rollersare responsible for the orientation of the longitudinal axis of eachfruit to a position parallel to the .axis of the rollers. In addition,the annular channel '42 and the angled shoulders 43 result in thetransversealignment of individual lemons with the dies 45, thuspresenting the most gently rounded surface of thelemon to the die forprinting. The die holder drum 4 is rotated in a counterclockwisedirection in the illustrations of Figure 2 by gear 21 which is driven bygear 29 secured to the shaft 14. Each individual die 45 contacts theinking ribbon at a point diametrically opposed from the point ofprinting. The inking ribbon tube is rotated in a clockwise direction, asseen in Figure 2, by gear 23 driven by gear 22 secured to the die holdershaft 13.

While we have exemplified the novel inventive aspects of our printingdie with reference to the problem of printing lemons, it Will beapparent that it is equally adapted for the impression of brands uponother cross sectionally circular articles and specifically oranges,grapefruit, apples, potatoes, tomatoes, nuts, avocados and other fruitsand vegetables.

We claim:

1. A printing die comprising an integral flexible resilient body havingboth a transverse and longitudinal trapezoidal section, the face of saidbody being defined by one parallel side having the smaller area and thebase of said body being defined by the other parallel side having thelarger area, said face bearing printing indicia, said base having aperipheral rounded flange protruding therefrom and extending completelyaround its periphery, said body being provided with a centrallongitudinal slit extending throughout the length thereof to enable saidbase to be laterally compressed and having a plurality of transverseslits extending thereacross to permit said base to be longitudinallycompressed, each of said longitudinal and transverse slits extendingthrough said peripheral flange and said base and terminating within saidbody, whereby said base may be contracted both laterally andlongitudinally to permit the same to be inserted into a die opening hav'ing an undercut groove to receive the rounded flange, the die openingbeing of shorter length and less width than the flanged base when in itsuncontracted state.

2. The printing die of claim 1 in which the face and a portion of theresilient body adjacent thereto comprises material of one hardness andthe remainder of the resilient body comprises a material of a greaterhardness, and wherein a portion of the materials are commingled so thatsaid flexible resilient material diminishes in rigidity and increases inpliability and resiliency as a functon of the distance within said bodyfrom said face.

References Cited in the file of this patent UNITED STATES PATENTS

